If certain switches are not specified, llvm-strip behaves as if
--strip-all were specified. This means that for testing, when we don't
want the stripping behaviour, we have to specify one of these switches,
which can be confusing. This change adds --no-strip-all to allow an
alternative way of suppressing the default stripping, in a less
confusing manner.
Reviewed by: jakehehrlich, MaskRay
Differential Revision: https://reviews.llvm.org/D61377
llvm-svn: 359781
Previously we did not report this.
Also this removes multiple lookups in the map
what cleanups the code.
Differential revision: https://reviews.llvm.org/D61322
llvm-svn: 359663
-t is --symbols in llvm-readobj but --section-details (unimplemented) in readelf.
The confusing option should not be used since we aim for improving
compatibility.
Keep just one llvm-readobj -t use case in test/tools/llvm-readobj/symbols.test
llvm-svn: 359661
We use both -long-option and --long-option in tests. Switch to --long-option for consistency.
In the "llvm-readelf" mode, -long-option is discouraged as it conflicts with grouped short options and it is not accepted by GNU readelf.
While updating the tests, change llvm-readobj -s to llvm-readobj -S to reduce confusion ("s" is --section-headers in llvm-readobj but --symbols in llvm-readelf).
llvm-svn: 359649
GNU objcopy uses bfd_elf_get_default_section_type to decide the candidate section type,
which roughly translates to our [a] (I assume SEC_COMMON implies SHF_ALLOC):
(!(Sec.Flags & ELF::SHF_ALLOC) || Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)))
Then, it updates the section type in bfd/elf.c:elf_fake_sections if:
if (this_hdr->sh_type == SHT_NULL)
this_hdr->sh_type = sh_type; // common case
else if (this_hdr->sh_type == SHT_NOBITS
&& sh_type == SHT_PROGBITS
&& (asect->flags & SEC_ALLOC) != 0) // uncommon case
...
this_hdr->sh_type = sh_type;
If the following condition is met the uncommon branch is executed:
if (elf_section_type (osec) == SHT_NULL
&& (osec->flags == isec->flags
|| (final_link
&& ((osec->flags ^ isec->flags)
& ~(SEC_LINK_ONCE | SEC_LINK_DUPLICATES | SEC_RELOC)) == 0)))
I suggest we just ignore this clause and follow the common case
behavior, which is done in this patch. Rationales to do so:
If --set-section-flags is a no-op (osec->flags == isec->flags)
(corresponds to the "readonly" test in set-section-flags.test), GNU
objcopy will require (Sec.Flags & ELF::SHF_ALLOC). [a] is essentially:
Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)
This special case is not really useful. Non-SHF_ALLOC SHT_NOBITS
sections do not make much sense and it doesn't matter if they are
SHT_NOBITS or SHT_PROGBITS.
For all other RUN lines in set-section-flags.test, the new behavior
matches GNU objcopy, i.e. this patch improves compatibility.
Differential Revision: https://reviews.llvm.org/D60189
llvm-svn: 359639
This is a fix for https://bugs.llvm.org/show_bug.cgi?id=41371.
Currently, it is possible to break the sh_link field of the dynamic relocation section
by removing the section it refers to. The patch fixes an issue and adds 2 test cases.
One of them shows that it does not seem possible to break the sh_info field.
I added an assert to verify this.
Differential revision: https://reviews.llvm.org/D60825
llvm-svn: 359552
Summary:
llvm-{objcopy,strip} (and many other LLVM binary utilities) accept
cl::opt style -long-option as well as many short options (e.g. -p -S
-x). People who use them as replacement of GNU binutils often use the
grouped option syntax (POSIX Utility Conventions), e.g. -Sx => -S -x,
-Wd => -W -d, -sj.text => -s -j.text
There is ambiguity if a long option starts with the character used by a
short option. Drop the support for -long-option to resolve the ambiguity.
This divergence from other utilities is accepted (other utilities
continue supporting -long-option).
https://lists.llvm.org/pipermail/llvm-dev/2019-April/131786.html
Reviewers: alexshap, jakehehrlich, jhenderson, rupprecht, espindola
Reviewed By: jakehehrlich, jhenderson, rupprecht
Subscribers: grimar, emaste, arichardson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60439
llvm-svn: 359265
llvm-objcopy currently emits an error if a section to be removed is
referenced by another section. This is a reasonable thing to do, but is
different to GNU objcopy. We should allow users who know what they are
doing to have a way to produce the invalid ELF. This change adds a new
switch --allow-broken-links to both llvm-strip and llvm-objcopy to do
precisely that. The corresponding sh_link field is then set to 0 instead
of an error being emitted.
I cannot use llvm-readelf/readobj to test the link fields because they
emit an error if any sections, like the .dynsym, cannot be properly
loaded.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D60324
llvm-svn: 358649
Summary:
This change takes the full list of bfd targets that lld supports (see `ScriptParser.cpp`), including generic handling for `*-freebsd` targets (which uses the same settings but with a FreeBSD OSABI). In particular this adds mips support for `--output-target` (but not yet via `--binary-architecture`).
lld and llvm-objcopy use their own different custom data structures, so I'd prefer to check this in as-is (add support directly in llvm-objcopy, including all the test coverage) and do a separate NFC patch(s) that consolidate the two by putting this mapping into libobject.
See [[ https://bugs.llvm.org/show_bug.cgi?id=41462 | PR41462 ]].
Reviewers: jhenderson, jakehehrlich, espindola, alexshap, arichardson
Reviewed By: arichardson
Subscribers: fedor.sergeev, emaste, sdardis, krytarowski, atanasyan, llvm-commits, MaskRay, arichardson
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60773
llvm-svn: 358562
Currently, YAML has the following syntax for describing the symbols:
Symbols:
Local:
LocalSymbol1:
...
LocalSymbol2:
...
...
Global:
GlobalSymbol1:
...
Weak:
...
GNUUnique:
I.e. symbols are grouped by their bindings. That is not very convenient,
because:
It does not allow to set a custom binding, what can be useful for producing
broken/special outputs for test cases. Adding a new binding would require to
change a syntax (what we observed when added GNUUnique recently).
It does not allow to change the order of the symbols in .symtab/.dynsym,
i.e. currently all Local symbols are placed first, then Global, Weak and GNUUnique
are following, but we are not able to change the order.
It is not consistent. Binding is just one of the properties of the symbol,
we do not group them by other properties.
It makes the code more complex that it can be. This patch shows it can be simplified
with the change performed.
The patch changes the syntax to just:
Symbols:
Symbol1:
...
Symbol2:
...
...
With that, we are able to work with the binding field just like with any other symbol property.
Differential revision: https://reviews.llvm.org/D60122
llvm-svn: 357595
Summary:
Some flags accepted by --set-section-flags and --rename-section can change a SHT_NOBITS section to a SHT_PROGBITS section. Note that none of them can change a SHT_PROGBITS to SHT_NOBITS.
The full list (found via experimentation of individually setting each flag) that does this is: contents, load, noload, code, data, rom, and debug.
This was found by testing llvm-objcopy with the gnu binutils test suite, specifically this test case: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=binutils/testsuite/binutils-all/copy-1.d;h=f2b0d9e90df738c2891b4d5c7b62f62894b556ca;hb=HEAD
Reviewers: jhenderson, grimar, jakehehrlich, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59958
llvm-svn: 357492
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=41293 and
https://bugs.llvm.org/show_bug.cgi?id=41045. llvm-objcopy assumed that
it could always read a section header string table. This isn't the case
when the sections were previously all stripped, and the e_shstrndx field
was set to 0. This patch fixes this. It also fixes a double space in an
error message relating to this issue, and prevents llvm-objcopy from
adding extra space for non-existent section headers, meaning that
--strip-sections on the output of a previous --strip-sections run
produces identical output, simplifying the test.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D59989
llvm-svn: 357475
This is a fix for https://bugs.llvm.org/show_bug.cgi?id=40007.
Idea is to swap the order of stripping. So that we strip sections before
symbols what allows us to strip relocation sections without emitting
the error about relative symbols.
Differential revision: https://reviews.llvm.org/D59763
llvm-svn: 357017
llvm-objcopy previously knew nothing about data in segments that wasn't
covered by section headers, meaning that it wrote zeroes instead of what
was there. As it is possible for this data to be useful to the loader,
this patch causes llvm-objcopy to start preserving this data. Data in
sections that are explicitly removed continues to be written as zeroes.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41005.
Reviewed by: jakehehrlich, rupprecht
Differential Revision: https://reviews.llvm.org/D59483
llvm-svn: 356919
Fix: r356853 + set AddressAlign to 4 in
Inputs/compress-debug-sections.yaml for the new group section introduced.
Original commit message:
Currently, llvm-objcopy incorrectly handles compression and decompression of the
sections from COMDAT groups, because we do not implement the
replaceSectionReferences for this type of the sections.
The patch does that.
Differential revision: https://reviews.llvm.org/D59638
llvm-svn: 356856
This patch fixes the reason of ubsan failure (UB detected)
happened after landing the D59638 (I had to revert it).
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/11760/steps/check-llvm%20ubsan/logs/stdio)
Problem is the following. Our implementation of GroupSection assumes that
its address is 4 bytes aligned when writes it:
template <class ELFT>
void ELFSectionWriter<ELFT>::visit(const GroupSection &Sec) {
ELF::Elf32_Word *Buf =
reinterpret_cast<ELF::Elf32_Word *>(Out.getBufferStart() + Sec.Offset);
...
But the test case for D59638 did not set AddressAlign in YAML. So address was
not 4 bytes aligned since Sec.Offset was odd. That triggered the issue.
This patch teaches llvm-objcopy to report an error for such sections (which should
not met in reality), what is better than having UB.
Differential revision: https://reviews.llvm.org/D59695
llvm-svn: 356853
Also fix up a couple of minor issues in the test being updated, where
FileCheck could match on incorrect output and fix the test case order to
match the struct order.
Reviewed by: grimar
Differential Revision: https://reviews.llvm.org/D59691
llvm-svn: 356746
Spec says about the first symbol table entry that index 0 both designates the first entry in the table
and serves as the undefined symbol index. It should have zero value.
Hence the first symbol table entry has no name. And so has to have a st_name == 0.
(http://refspecs.linuxbase.org/elf/gabi4+/ch4.symtab.html)
Currently, we do not emit zero value for the first symbol table entry.
That happens because we add empty strings to the string builder, which
for each such case adds a zero byte:
(https://github.com/llvm-mirror/llvm/blob/master/lib/MC/StringTableBuilder.cpp#L185)
After the string optimization performed it might return non zero indexes for the
empty string requested.
The patch fixes this issue for the case above and other sections with no names.
Differential revision: https://reviews.llvm.org/D59496
llvm-svn: 356739
Currently, llvm-objcopy incorrectly handles compression and decompression of the
sections from COMDAT groups, because we do not implement the
replaceSectionReferences for this type of the sections.
The patch does that.
Differential revision: https://reviews.llvm.org/D59638
llvm-svn: 356738
GNU objcopy can support output formats like elf32-i386-freebsd and
elf64-x86-64-freebsd. The only difference from their regular non-freebsd
counterparts that I have observed is that the freebsd versions set the
OS/ABI field to ELFOSABI_FREEBSD. This patch sets the OS/ABI field
according based on the format whenever --output-format is specified.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D59645
llvm-svn: 356737
If the compression was used and we had a symbol not involved in relocation,
we never updated its section and it was silently removed from the output.
Differential revision: https://reviews.llvm.org/D59542
llvm-svn: 356554
This fixes the https://bugs.llvm.org/show_bug.cgi?id=40980.
Previously if string optimization occurred as a result of
StringTableBuilder's finalize() method, the size wasn't updated.
This hopefully also makes the interaction between sections during finalization
processes a bit more clear.
Differential revision: https://reviews.llvm.org/D59488
llvm-svn: 356371
For ELF, we accept but ignore --only-keep-debug. Do the same for llvm-strip.
COFF does implement this, so update the test that it is supported.
llvm-svn: 356207
This patch changes llvm-objcopy's behaviour to not strip sections that
are in segments, if they otherwise would be due to a stripping operation
(--strip-all, --strip-sections, --strip-non-alloc). This preserves the
segment contents. It does not change the behaviour of --strip-all-gnu
(although we could choose to do so), because GNU objcopy's behaviour in
this case seems to be to strip the section, nor does it prevent removing
of sections in segments with --remove-section (if a user REALLY wants to
remove a section, we should probably let them, although I could be
persuaded that warning might be appropriate). Tests have been added to
show this latter behaviour.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41006.
Reviewed by: grimar, rupprecht, jakehehrlich
Differential Revision: https://reviews.llvm.org/D59293
This is a reland of r356129, attempting to fix greendragon failures
due to a suspected compatibility issue with od on the greendragon bots
versus other versions.
llvm-svn: 356136
This patch changes llvm-objcopy's behaviour to not strip sections that
are in segments, if they otherwise would be due to a stripping operation
(--strip-all, --strip-sections, --strip-non-alloc). This preserves the
segment contents. It does not change the behaviour of --strip-all-gnu
(although we could choose to do so), because GNU objcopy's behaviour in
this case seems to be to strip the section, nor does it prevent removing
of sections in segments with --remove-section (if a user REALLY wants to
remove a section, we should probably let them, although I could be
persuaded that warning might be appropriate). Tests have been added to
show this latter behaviour.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41006.
Reviewed by: grimar, rupprecht, jakehehrlich
Differential Revision: https://reviews.llvm.org/D59293
llvm-svn: 356129
error() was previously cleaned up from CopyConfig, but new uses were introduced.
This also tweaks the error message for --add-symbol to report all invalid flags.
llvm-svn: 356105
When --compress-debug-sections is given,
llvm-objcopy removes the uncompressed sections and adds compressed to the section list.
This makes all the pointers to old sections to be outdated.
Currently, code already has logic for replacing the target sections of the relocation
sections. But we also have to update the relocations by themselves.
This fixes https://bugs.llvm.org/show_bug.cgi?id=40885.
Differential revision: https://reviews.llvm.org/D58960
llvm-svn: 355821
When --compress-debug-sections is given, llvm-objcopy do not compress
sections that have "ZLIB" header in data. Normally this signature is used
in zlib-gnu compression format. But if zlib-gnu used then the name of the compressed
section should start from .z* (e.g .zdebug_info). If it does not, then it is not
a zlib-gnu format and section should be treated as a normal uncompressed section.
Differential revision: https://reviews.llvm.org/D58908
llvm-svn: 355399
Summary:
This removes calls to `error()`/`reportError()` in the main driver (llvm-objcopy.cpp) as well as the associated argv-parsing (CopyConfig.cpp). `logAllUnhandledErrors()` is now the main way to print errors.
There are still a few uses from within the per-arch drivers, so we can't delete them yet... but almost!
Reviewers: jhenderson, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, jakehehrlich, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58316
llvm-svn: 354600
Sid Manning